Maritime transport plays a very important role in international trade, and commercial ships are a suitable tool for transporting all kinds of goods. Due to the progress of other types of transportation methods such as the aviation industry, sea transportation is still very important, so that about 90% of the transportation of goods in international trade worldwide is carried out by one of the types of commercial ships. Maritime trade and transportation has been prevalent since the dawn of civilization, in such a way that the Sumerians established regular trade in the Middle East region before Christ and covered all the coasts of this region for the purpose of transporting goods. From the beginning, merchant ships referred to the types that were used to carry cargo.

Types of commercial ships

1. General cargo ship (general goods)
2. Dry bulk carrier
3. Oil tanker ship
4. Face-to-face ships
5. Container ship
6. Passenger ships
7. LNG ship
8. Refrigerated ship
9. Cattle ship
10. Dube Bar ship
11. Chemical tankers
12. Sea tugs

Charter ship

Today, modern commercial ships are designed and built with the same definition but in different sizes and shapes, which manage almost 90% of world trade through sea transportation. Commercial ships can be as small as a 6-meter dive boat, or as large as 415 meters in length.

According to their size and structure, ships are used to carry three main categories of cargo; Including dry, liquid and specialized cargo. Dry cargoes such as bulk, general goods, large furnaces and containers, liquid cargoes such as oil, petroleum, as well as chemicals and liquefied gases, and specialized cargoes include passengers, livestock and heavy projects. In this article, we will review the types of commercial ships.

1. General cargo ship (general goods)

Although bulk carriers and container ships are used more today, general cargo ships are still in service for loading and storing a wide range of goods.

This range includes many goods such as forest products, heavy machinery, automobiles, industrial machinery, food and containers. The number of general ships is much more than other commercial ships. Usually, the loads that are prepared for transportation by these ships are packed and palletized so that the cargoes are less damaged and the space of the ship is used properly. Also, loads that occupy a lot of space in these types of ships can be loaded by crane.

2. Dry bulk carrier

As can be seen from the name of these ships, bulk carriers are used for unpackaged and dry cargo. The cargoes carried in these ships are without any special packaging, including grain, ore, cement, coal, chemical fertilizer and other similar cargoes.

The size of these ships depends on the type of cargo they carry, and their sizes vary from small ships to giant ships with a capacity of 400,000 tons. These ships are loaded and unloaded using many equipment such as conveyor belts, pumps, etc. From the middle of the 19th century, such ships began to travel in the seas. Today, however, bulk carriers make up a third of the world's commercial fleet. The deck of this type of ship is flat and watertight doors are installed throughout it to protect the cargo from water leakage. The longest dry bulk carrier is about 343 meters long.

One of the important features of bulk carriers is their very low cost, because these ships are very large and can accommodate many goods without packaging. The purpose of building these ships was to avoid high costs for packing and loading. In bulk ships, the engine room and passenger accommodation are located at the bottom of the ship, i.e. the heel, and in order to maintain balance, an additional water tank is built in the front part. In order to prevent possible injuries and to establish complete balance when the ship is sailing without cargo and empty, tanks are also installed in the corners and floors of the warehouses, which are filled with water in such a situation.

3. Oil tanker ship

With the increasing extraction of oil and according to the urgent need of industrialized countries, the progress in the field of shipbuilding reached a point where in the early seventies, Japan began to build oil tankers with a capacity of Five hundred thousand tons, and currently, according to the statistics and figures presented, Oil tankers account for the highest percentage of sea transportation.

These ships are used to transport crude oil and petroleum products. Oil tankers are produced in extremely large sizes that have to travel in deep seas. Among the technical features of these ships, we can mention insulation, structural resistance and oil pumping system.

Sometimes up to two million barrels of oil can be transported using these ships. Due to the very large size of these ships, loading and unloading in ports is not possible and this process is done in special places. The surface of the deck in oil tankers is covered with pipes and pumps, which are special for the transportation of crude oil, and newer and more advanced models have special coatings to prevent oil from leaking into seawater.

The capacity and size of these tankers are different, but they have defined limits for their classification, which are divided according to the capacity of crude oil:

• Indian size: between 10,000 and 30,000 tons
• Indian Max: between 35,000 and 50,000 tons
• Pana Max: between 55,000 and 75,000 tons
• Afra Max: between 80,000 tons and 115,000 tons
• Suez Max: between 120,000 and 150,000 tons
• (Very large crude carrier (VLCC): between 200,000 and 300,000 tons
• (Ultra Large Crude Carrier (ULCC): more than 300,000 tons, the largest of which has a capacity of 550,000 tons.

4. Face-to-face ships

Roro ships, for transporting moving cargo such as trucks, cars, trailers, semi-trailer trucks, railway cars, cargoes that can be loaded and unloaded independently such as containers on trailers, cargoes that are moved using special equipment such as containers, goods It is designed for heavy weight and palletized goods as well as passengers traveling by car.

The biggest advantage of these vessels is their speed, the use of advanced equipment is the reason for their high speed. These ships also have multiple vehicle decks that include parking lanes and are connected by one or more loading ramps for shore access. The existence of different and movable floors in the ship has made loading to be done in the best way.

Ro-Ro ships are divided into four categories:

• Multipurpose RO-RO

• RO-MAX is used to transport passengers and goods.

• RO-ROs that are equipped with cranes.

• RO-ROs that are used in the import and export industry in the automotive industry.

5. Container ship

As expected from the name of these ships, they are only responsible for transporting containers with all kinds of cargo packed in them. The warehouse in container ships is mostly divided in such a way as to accommodate the containers in an orderly manner; Of course, modern container ships no longer have separate warehouses and the entire loading space is integrated, which makes unloading and loading faster.

Today, the use of containers has been able to create a revolution in the methods of transporting goods, both for the ease of transportation and protection of goods, and economically. These advantages are especially noticeable in uniform carry. In one-way transportation, the carrier company receives the cargo from the sender at the origin (factory or warehouse) and delivers the goods to the recipient at the destination. This method is called Door to Door. Another advantage of containers is that they can be transported by any means of transport, including ships, trucks, railways, and even airplanes.

Containers are different in terms of use; Such as containers for light and heavy loads, refrigerated containers for perishable goods and open containers that can be loaded or unloaded from the roof.

Currently, container ships are divided into 6 separate groups:

A) FEEDER ships with a loading capacity of 100 to 500 TEU

b) FEEDER MAX ships with a loading capacity of 500 to 1000 TEU

c) Ships (HANDY) with loading capacity of 1000 to 2000 TEU

d) Ships (SUB PANAMAX) with a loading capacity of 2000 to 3000 TEU

e) PANAMAX vessels with a loading capacity of at least 3,000 TEU

f) Ships (POST PANAMAX) with a loading capacity of more than 4000 TEU

6. Passenger ships

With the expansion of the tourism industry, significant progress has been made in the construction of passenger ships. General changes in ship building, such as the creation of well-equipped and modern resorts, have made these ships different from other types of ships. Passenger ships are used to transport passengers and vehicles over short distances. These ships are built with a capacity of 3000 to 6000 people and a speed of 30 knots.

The engine room of these ships was initially located in the middle part, the water and fuel tanks covered the lower parts of the ship, and the heel of the ship was dedicated to the residence of the sailors, the kitchen and the reception hall for the guests. But in the production of newer and modern models, the passenger reception area has been moved to the top of the ship. Some of these ships have advanced facilities such as luxury hotels and luxurious restaurants, swimming pools, cinemas, etc. for marine entertainment, and car ramps, private cabins, and hospitals equipped with specialist doctors are among the additional facilities of these passenger ships.

Types of passenger ships

• Large liner ship: used for long trips.

• Ferry: These ships are used for trips and short distances.

• Cruise ship: This type of ship is also used for both long and short trips.

• Passenger ship

7. LNG ship

LNG is the result of natural gas condensation process, which can only be transported to consumption markets by LNG ships. After the transfer, this product turns into a gas again in the terminals by conversion systems. In fact, LNG gives consumers the ability to use a clean and economical fuel. Today, ships carrying LNG, with very high safety, continuously dock at the terminals of countries such as Japan and Spain and provide the energy needed by these countries for both domestic and industrial use.

In fact, the stable global flow of LNG shows the high safety of this fuel in its transmission to consumers. The use of double-walled ships and the implementation of strict industry standards, in addition to effective risk management, have made this industry an exemplary industry in terms of safety. Over the past 45 years, these ships have moved more than 450,000 cargoes over hundreds of millions of kilometers.

In these ships, double-walled tankers are designed to prevent leakage or breakage in accidents, which are transported under very low pressure and temperature conditions (-256 degrees Fahrenheit).

8. Refrigerated ship

Use of refrigerated ships to transport food products that are necessary and used daily, as well as products that are perishable and perishable in a short time. He says These refrigerators play a very important role in transportation and can deliver the cargo to its destination without any damage. Cargoes such as fruit, meat, perishable food, etc. are loaded and protected in the well-equipped and suitable refrigerators of these ships. Ports to which refrigerated ships travel must have the necessary coastal facilities.

With the arrival of container ships that have the ability to carry refrigerated containers, the market's inclination toward this type of ships has decreased and caused the lack of acceptance in the market of refrigerated ships; In such a way that there are currently no orders for the construction of new ships of this kind.

9. Cattle ship

Livestock ships are used to transport animals such as cows, sheep, etc. Without the help of such ships, it is very difficult or completely impossible to transport livestock. These types of ships are capable of carrying 2,000 to 2,500 tons of weight in terms of carrying capacity. Some of these ships have an open roof, which prevents the animals from being harmed by overcrowding.

10. Dube Bar ship

This ship is designed to carry other vessels, especially barges, and has a crane for loading and unloading barges. Buoyancy boat is a rectangular cube with a hollow space that usually does not have a motor or propellant and it is pulled or pushed forward by a boat or other float on the water. Barges are used to transport goods to shallow docks and unnavigable rivers.

To make this means of transportation, two traditional and block methods are used. In the traditional method, which is suitable for making small doubles, the wide sheets are first connected to each other, and then the corners are welded to that part. Finally, these sheets are connected to the built frames.

In the block method, the dobe is made of separate blocks that are completed completely separately at first and will be connected to each other in the end. This method requires a lot of precision during production, but its construction time is greatly reduced.

It should be noted that if the standards are not met during production, the blocks will not be paired with each other when connected. This device is used to carry various loads, which changes depending on the intended load of the type of trailer so that it is suitable for carrying the load. Such as trucks for transporting liquids, cars and grains.

11. Chemical tankers

Special types of tankers are used to transport liquid chemicals and vegetable oils. Liquid chemical cargoes are divided into three categories of IMO I, II, III based on the level of flammability, toxicity, corrosion and reactivity. Due to the lack of accurate and complete information on the classification of tankers, the exact capacity of chemical tankers in the world is not possible. The body of these tankers is made of stainless steel. The IMO II type tanker is used for certain chemical cargoes and costs more to rent than the IMO III type.

Shipments of chemicals are divided into three categories:

• Organic chemicals

• Inorganic chemicals

• Vegetable oils

12. Sea tugs

Marine tugboats are built to pull and push various types of vessels. Tugs start at Four hundred and forty seven kW, the most powerful of which goes up to about Eight thousand two hundred and seventy seven kW. Their length is 11 to 61 meters and their width is 6.5 to 17 meters.

• Sea tug

• Types of towing

• Common towing

• Side to side or pushing (shifting or pushing)

• The advantage of side-to-side towing (shifting)

• Applications of tugs

• To undock or moor ships

• Carrying guide

• To launch the barge

• Separating the ship from the berth with a sea tug

One of the most important principles of tugs is the strength of the connecting rope. This rope must be strong enough so that it does not break in any situation, and also the strength of the connection to the float, the rope must be strong so that it does not get damaged during towing.

13. Charter ship

It is interesting to note that the word charter was used in the shipping industry before charter tickets became popular. Charter ship was the first term to be used, and later it found its way into other areas of transportation.

Although the word charter has been introduced in other areas and its use has become more widespread, it is still used in sea transit. There are different types of charter ships, which float in seas and oceans. Ships, boats, and other marine vehicles are often owned by natural persons, used for purposes such as recreation and transportation, and may be owned by a specific body or organization.

Otherwise, most legal entities do not use the ships for purposes such as carrying cargo and transporting passengers, and lease them to third parties who use them for various purposes. This type of ship, be it pleasure, passenger or cargo, is known as a charter ship.

Leasing is known as charter. Chartering is an important concept in the global maritime trade sector, which takes many forms. All the conditions included in the charter ship rental are necessary for both parties of the agreement and include various clauses and possible scenarios.

In accordance with maritime transport laws, an official document must be drawn up for any type of ship charter. The ship owner is the first party of the charter ship contract, and the person or organization that needs the ship is the recipient of the charter, and the things that should be mentioned in the charter ship contracts, including the rental time, costs, installments, regulations related to use, as well as detailed expert reports from The state of the ship.

In the agreement that is written for the charter ship, the ports of origin, destination, transit Interfaces and load limits, if any, are mentioned. Most voyage charters are carried out by charterers who need to ship specific and limited cargo to another location. For this, they contact ship owners and charter a ship for the trip.

The duration of the charter ship contract is quite definite and it is called the time when the charterer is allowed to finish the loading work at the port. When the owner pays the shipping costs, the tenant is expected to expedite the process. If the time of this work is more than the time specified in the contract, the ship charterer must pay a penalty.

The main owner must pay all the costs related to the ship's fuel and the ship's staff, etc.; For this reason, the owners request a large rate from the charterer to compensate for such costs. The ship owner is responsible for freight and other payments.

Charter ship conditions and features

It is true that the charterer takes control of the ship, but the maintenance of the chartered ship is still under the authority of the ship owner. In long-term agreements, the rate is calculated daily and payments are made quarterly.

If there is a problem with the ship, the charterer is exempted from daily payment; For example, if a ship gets into trouble due to bad weather and stops moving, there is no need to pay a daily fee for the time spent, or if the ship needs repairs, the time needed to repair it is regardless of the rent. .

The charterer can choose the ship's crew and pay the expenses incurred during the voyage.

When writing the ship charter contract, mention the following:

• Name of the ship

• Its specifications, capacity and facilities

• Specifications and amount of cargo

• Ports or places of loading and unloading

• Freight rates

• How to pay the fare and when and where it is paid

• The date of the ship's arrival at the port of loading

• Duration and permitted speed of unloading and loading

• Amount of ship delay damage

In this article, types of commercial ships were introduced. The presented division does not cover all existing ships and only the types of ships that are more used in transporting goods and passengers were mentioned. There are also groups such as livestock vessels, drilling vessels, fishing vessels, floating cranes, etc., which are not included in the contents of this page.